Waves Basics Flashcards
What is displacement of a wave and what is it’s symbol?
Displacement, X , measures how far from its equilibrium position a point in the wave has moved.
Usually the y axis on a wave diagram.
What is a progressive wave?
A wave that carries energy without transferring any material. Caused by oscillation of particles in a medium.
In terms of measuring waves, what is X and what is it measured in?
Displacement measures in meters
What is a waves amplitude and what is its symbol?
Symbol: a
It is he maximum displacement of a wave. The max movement from the equilibrium position to a trough or crest.
What is a waves wavelength and what is its symbol?
Symbol: lander
It is the length, in meters in one complete wave cycle or oscillation. E.g the distance between to crests.
What does the symbol a stand for and what is it measured in?
Amplitude measured in meters
What does the lander symbol stand for and what is this measured in?
Wavelength measured in meters.
What is the period of a wave? What is its symbol?
Symbol: T
This is the time in seconds, for 1 complete cycle or oscillation to take place. E.g time between two crests
What is a waves frequency and what is its symbol?
Symbol: f
Measured in Hz, frequency is the number of cycles or oscillations per second.
What is a waves phase difference? What is it measured in?
This is the difference between to identical points in two different waves. The amount one wave lags behind another.
Mesured in degrees or radians
What equation links frequency and a waves period?
Frequency = 1/period f= 1/T
What are two equations to find a waves speed?
C=f x lander
C = distance/time
Is phase difference the same as
Path difference?
NO
What is path difference and what is it measured in?
The amount by which the path travelled by one wave is longer than the path travelled by another wave.
Measured in wavelengths or meters
Which waves oscillate at right angles to the direction of travel or the wave?
Transverse waves
What type of waves are electromagnetic waves?
They are transverse waves.
What are transverse waves?
They are waves that the vibrations are at right angles to the direction if travel.
Examples of transverse waves are
All electromagnetic waves
Water ripples
Waves on ropes
String instruments
What are the two ways of representing transverse waves?
Displacement against distance graphs,
Displacement against time for a point as the wave passes.
Longitudinal waves are …
Waves that have vibrations along the direction of travel.
Waves that oscillate along the direction of travel are called?
Longitudinal waves
What type of wave is sound
Longitudinal
In a longitudinal wave what are crests and troughs called?
Compressions and rarefractions
Examples of longitudinal waves are
Sound
P- waves in earthquakes
A slinky on a table that is knocked at one end.
What is a polarised wave?
A wave that only oscillated in one plane or direction.
How do polarising filters work.
Light is a mixture of different polarisations.
A polarising filter only allows through oscillations in a certain direction.
The light that gets through is polarised the same way.
How can two polarised filters be arranged to not allow light through?
They should each only allow light through that is at a right angle I the other filter.
How do polarised googles or sunglasses work?
When light is reflects of some surfaces it becomes partially polarised.
Polarised Filters in the glasses can filter out this light to prevent glare from the surface.
How can polarisation improve tv or radio signals.
The radio waves are polarised by he orientation of the rods transmitting them.
To get a good signal the receiving Ariel should be aligned the same.
That’s why having tv Aries are horrizontal.
Uses of polarising lenses.
Sunglasses
Photography
Experiments.
